Explosions, evolution and energy: top 10 Cosmos explainers

If you get stuck for a conversation topic on New Years Eve, fascinate your companion with a few facts from our best explainers from 2016.

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Where do deep space probes get their power?

As you are reading this, the Voyager 1 spacecraft, carrying its valuable gold-plated record describing life on Earth, is more than 20.1 billion kilometres away – or 135 times the distance between the Earth and the sun. It is, though, still sending back a faint signal, but how is this possible?Read more

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What is energy?

Any physics textbook will tell you energy is “the capacity to do work”. But isn’t this definition kind of unsatisfying? It’s a bit like Plato’s definition of man as a “featherless biped” – it’s hard to poke holes in the reasoning, but you can’t help but feel something is missing. Read more

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What is light?

Imagine you’re in a park, looking at a leaf on the branch of a tree. We know light bounces off the leaf to your eye to tell you it’s green – but what is light, exactly?Read more

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The dark side of the universe – a primer

Over the past 40 years astronomers have realised that everything we can see – all the stars, planets and galaxies – make up less than 5% of the entire universe. What is the rest? The short answer is, we have no idea. Read more

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Why does a broken leg mean death to a racehorse?

Tragedy struck last year’s Melbourne Cup, Australia’s most famous horse race, when the much-loved English stayer Red Cadeaux was euthanised after breaking his left foreleg during the race. Sadly, the 10-year-old’s misfortune is not an isolated incident and the all-too-common deaths of thoroughbreds are used by racing’s opponents to demand an end to the sport. So why do these big powerful animals break limbs so easily? And why is an injury that is painful but usually easily treatable in a human, a death sentence for a horse?Read more

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Quantum computing for the qubit curious

What is quantum computing? Regular computers operate according to strict rules of logic. But tiny quantum objects – such as electrons, or photons of light – can break those rules. Quantum computing is the idea that we can use this quantum rule-breaking to process information in a new way – one that’s totally different from how regular computers work.Read more

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Particle physics: a primer to the theory of (almost) everything

The Standard Model categorises all of the particles of nature, in the same way that the periodic table categorises the elements. The theory is called the Standard Model because it is so successful it has become “standard”. There are, however, still a few kinks to be ironed out (as well as a couple of whopping omissions). That’s why it is sometimes called the “Theory of Almost Everything”. Read more

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Why lithium-ion batteries are prone to exploding

On 5 October 2016, a Baltimore-bound Southwest Airlines flight was evacuated at its departure gate at Louisville airport in Kentucky. The reason: a Samsung Galaxy Note 7 smartphone that caught fire, thanks to its lithium-ion battery overheating. Samsung phones are not the only devices at risk. Theoretically, any device containing a lithium-ion battery can suffer the same fate. Read more

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Where did we come from? A primer on early human evolution

The story of human origins is a messy one. Each bone fragment that’s unearthed or ancient genome that’s decoded adds a new piece to the puzzle – and it doesn’t necessarily make the picture any clearer. Read more